Why bacterial cellulose is a desirable material

The word “cellulose” generally evokes plant fibers, but the biopolymer can also be made by bacteria. Plant cellulose is ubiquitous, but it suffers from disadvantages such as contamination with lignin, wax, and hemicellulose.

Bacterial cellulose (BC), on the other hand, is free from impurities such as lignin and wax, and exhibits water retention and other mechanical properties. BC is becoming more and more popular worldwide with its leather-like appearance and properties.

Although BC has been known for decades, research on it has increased in the last 2-3 years because the world wants materials with better functionalities and better looks that are made without harming animals. Scientists are trying to solve two problems – how to make BC cheaper; and how to make it more functional. The search for more climate-friendly materials also leads scientists to BC. Leather manufacturing uses a lot of water and chemicals; Animals also release huge amounts of methane.

BC can substitute leather in the manufacture of products such as bags. “Vegan leather” is on the rise in the West. German company ScobyTec and Brazilian company Intervém Design make BC fashion products like bags and planters.

BC polymers are also used in other industries such as biomedicine. “BC, made from gelling agents such as sodium alginate, chitosan, polyethylene glycol and gelatin, can also be used as a carrier for bioactive compounds such as antibiotics,” says a scientific paper by Dr. Ahmed Saleh et al. from the National Research Center. Egypt, published in Nature. Wound dressing is emerging as a key application of BC.

“BC and BC-derived materials are essential for the development of pure and environmentally sound functional materials,” says another paper on the subject, published by scientists at the Chennai-based Central Leather Research Institute, which is part of the Council for Scientific and Industrial Research subject to (CSIR).

dr Debasis Samanta, one of the authors of the CLRI paper, narrated quantum that the institute’s efforts were directed towards combining other polymers with BC. Samanta and his team have succeeded in combining polytriazole with BC using click chemistry techniques. He said polyurethane could be “immobilized” in BC in a similar way and such a material would be cheaper.

cost reduction

“The high cost of BC production poses a challenge in its commercial introduction,” says Dr. Saleh in his article. One way to reduce costs is to increase yield, which means identifying strains of bacteria that can produce more.

The most commonly used bacteria to produce BC are the Komagataeibacter.

Saleh and his team identified a novel BC-producing strain called Lactiplantibacillus plantarum and isolated it from rotten fruit. In experiments, this bacterium proved to be high-yielding.

Desired Properties

An emerging branch of science is “engineered living materials” or ELMs. Because BCs are produced by bacterial cultures, it is possible to impart desirable properties by manipulating the bacteria. Research is now focused on genetic engineering of Komagataeibacter and other organisms such as Saccharomyces cerevisiae with which to co-cultivate Komagataeibacter. Scientists at Imperial College London have succeeded in genetic manipulation Komagataeibacter rhaeticus.

Black dye is one of the most consumed dyes in the world and one of the most difficult to replicate using sustainable dyeing methods. Scientists have been experimenting with the biosynthesis of the dark melanin pigment eumelanin Komagataeibacter rhaeticus. The experiment seems to have been successful.

In an awaiting review Kenneth Walker et al. say: “We demonstrate here that the manufacture of pigmented cellulose from K. rhaeticus can be produced in large enough quantities for fashion product prototyping.”

They further note that their work underscores the value of genetic engineering “to design and construct strains intended to breed materials with desired properties; in this case with a selected color that has grown into the material rather than being added later through an industrial chemical dyeing process.”

Therefore, by the looks of it, BC is becoming an important industrial product.